How do we get exposure to PM 2.5 in our communities? 

Because the City of Kingston is located in a valley, it is subject to temperature inversions. 




Normally, colder air is higher up in the atmosphere, but in a valley such as ours, especially in the winter, daylight hours are fewer and  the earth’s heat dissipates quickly, keeping colder, denser air at the earth’s surface. Pollutants such as vehicle exhaust or woodsmoke  are trapped close to the earth, where we breathe.  The valley acts as a “sink” that can trap pollutants for days. The above figure, generated by the US National Weather Service, explains this phenomenon. 

Some History on Temperature Inversions, and why we need to keep track of them

Historically, temperature inversions have had dire consequences and have caused large numbers of deaths within days of occurrence. They are referred to as smog events. Smog contains particulate matter, nitrogen oxides, and volatile organic compounds.

Some notable smog events and locations include:
 
The Great Smog of London: In the winter of 1952, for five days a temperature inversion combined with coal, wood, and industrial pollution to form deadly smog that resulted in 4000 deaths in the immediate aftermath, and up to 12,000 more into the summer.

NYC has experienced  several smog emergencies due to weather inversions over modern history; Notable events occurred in 1953, 1963, and in 1966. During this last one, up to 200 people are estimated to have died over the three days from November 23-25, with another 200 in the ensuing months.

Salt Lake City has one of the most frequent inversion occurrence rates in the US. This leads to serious health consequences, even for people with no underlying conditions.

The Hudson Valley is subject to these inversions as well, as the mountains keep in the colder, trapped air, capped by the warmer air, and this does not allow pollutants to escape.

How to know when you are experiencing a temperature inversion

You may be experiencing a temperature inversion if you exit your home and take note of any of the following: 

-A clear night sky with little to no clouds and little to no wind
-Presence of dew 
-Horizontal smoke patterns
-Dust getting kicked up from a road and remaining suspended midair
-Fog in low-lying areas 

A temperature inversion will typically form in the evening under clear skies with little to no wind when the sun sets and the earth’s surface cools. Temperatures will begin to differ between ground level and heights as low as 8-10 feet above the ground. When these differences are greater, the more severe the inversion. The decay time for an inversion from its initiation can exceed ten hours. This means that particulate matter and other forms of pollution will remain airborne close to the surface of the earth making us more susceptible to the health consequences of inhalation. It is very important that if you witness any of the above phenomena and feel you are experiencing a temperature inversion, do not burn wood or idle in your vehicle.  

All above information from https://myfarmlife.com/2017/spot-temperature-inversion/

Other resources:

https://agriculture.mo.gov/plants/pdf/BASF_TechBulletin_TemperatureInversion_highres.pdf
https://www.weather.gov/media/lzk/inversion101.pdf